In U.S. Pat. No. 5,039,250 issued Aug. 13, 1991, and Canadian patent no. 1,304,975, issued Jul. 14, 1992, there is disclosed a sediment control barrier to be installed on a ground surface including a transversely stiff folded longitudinal sheet folded downward about a longitudinal axis to form an apex. The longitudinal edges of the sheet are secured to the ground. The sheet has a chosen permeability selected according to its intended application.
While this device has proven successful, the mesh sheets provide constant permeability, which does not accommodate a range of flows. During high flow volume, for a constant permeability, barrier sheets can become clogged, resulting in the device functioning as a ditch block rather than a porous berm. In addition, such a device does not easily conform to a variable height ground surface.
The present invention is directed towards providing an improved sediment control barrier.
Therefore, according to an aspect of the invention, there is provided a sediment control barrier for installation on a sloped surface such as a ditch that is structured to conform to the sloped surface. In one aspect of the invention, the sediment control barrier comprises a sheet having a length and a height, and a lengthwise extending edge that is secured to the ground across the sloped surface, the sheet extending upwards away from the sloped surface to a distal edge; and slots in the sheet extending downward into the sheet from the distal edge. The slots may have any of various shapes, and may decrease in width away from the distal edge.
In a further aspect of the invention, there is provided a sediment control barrier, comprising a ground contacting surface having a length suitable for controlling fluid flow across ground, barrier material extending perpendicularly from the ground contacting surface, means for securing the ground contacting surface to the ground; and the barrier material having a graded permeability from a first, lower, non-zero permeability adjacent the ground contacting surface to a second, higher, permeability away from the ground contacting surface.
Preferably, the barrier is formed of a self-supporting triangular structure. The barrier material may be made permeable by any of a variety of ways, as for example using slots, or openings. Particularly when slots are used, increasing permeability of the sediment control barrier away from the ground contacting surface, and the consequential differing lengthwise compressibility of the barrier, allows the ground contacting surface to flex and conform to a ground surface. The sediment control barrier is typically used for sediment control on sloped surfaces such as in ditches, but also has utility as a barrier for wind control. The barrier material is preferably itself made of water impermeable material.
In a further aspect of the invention, a sediment control barrier is provided with velocity dissipating legs.
In a still further aspect of the invention, plural barriers may be arranged along a ditch or other sloped surface, with variable permeability, and the upslope barrier having greater permeability.
These and other aspects of the invention are described in the detailed description of the invention and claimed in the claims that follow.